Inductive proximity sensors may be employed in a variety of applications to sense the distance of an adjacent object such as an electrically conducive or magnetizable object. As the object comes into range of the inductive proximity sensor, the material of the object disrupts and/or changes the magnetic field of the sensor which, in turn, causes a change in the current used to generate the magnetic field. The change in the current may be generally related to the distance the object is from the sensor. Accordingly, by measuring the change in the current the distance of the object from the inductive proximity sensor may be determined. Such inductive sensors are particularly useful in welding processes including automated welding processes.
In order to maximize the sensing range of the inductive proximity sensor, it is common practice to package the inductive proximity sensor in a thin metal housing with a diameter only slightly larger than the diameter of the inductive sensing coil such that only a minimal amount of metal is proximate the inductive sensing coil. This is because the metal of the housing may adversely impact the sensing range of the inductive proximity sensor by attenuating the magnetic field of the coil. Accordingly, the less metal that is used in the housing, the greater the sensing distance of the inductive sensing coil. However, such inductive proximity sensors are subject to damage and frequent failures as the thin metal housing does not sufficiently protect the inductive sensing coil from mechanical impact. As a result, the inductive proximity sensors must be frequently repaired and/or replaced due to damage to the inductive proximity sensor. The cost of repairing and replacing the inductive proximity sensors, in addition to production and/or manufacturing downtime caused by sensor failures, and/or damage may significantly increase manufacturing costs and, as a result, the cost of goods manufactured using inductive proximity sensors.
Accordingly, a need exists for improved inductive proximity sensors.